The invention relates to a distributor of the type used in hydraulic systems for controlling the flow of hydraulic fluid to and from one or more hydraulic actuators, for example, hydraulic cylinders, pumps, or motors. Such installations are used to control the operation of machines, machine tools and civil engineering equipment, in aviation and on various vehicles.
An hydraulic distributor is interposed between one or more hydraulic generator hydraulic actuators, and provides a circuit for the supply of fluid under pressure and a return circuit. It is normal practice to group several distributors in a single control position, especially on vehicles or on civil engineering equipment, in such a way as to make several hydraulic connections simultaneously in order to operate several hydraulic actuators, such as several cylinders, for example, at the same time.
Each distributor includes a slide that is able to move through several positions. The distributor is said to be of the proportional type when, for a given movement of the slide, a given constant output is obtained in the operating circuit independent of the conditions of force or couple encountered by the receiver, cylinder or similar device.
The present invention especially relates to a proportional hydraulic distributor of this type which has, in addition, a sensor for sensing the value of the pressure required by the actuator that is being operated by the distributor.
In a multiple hydraulic actuator hydraulic system, the sensor, known as a "load sensor", transmits the value of the highest pressure required by any of the actuators to a pressure regulator that is a part of the hydraulic system. This allows the pressure to be regulated to the exact value necessary for feeding the actuators.